It is important to acquire the composition of Si1-xGex layer, especially that with high Ge content, epitaxied on Si substrate. Two nondestructive examination methods, double crystals X-ray diffraction （DCXRD） and mi...It is important to acquire the composition of Si1-xGex layer, especially that with high Ge content, epitaxied on Si substrate. Two nondestructive examination methods, double crystals X-ray diffraction （DCXRD） and micro-Raman measurement, were introduced comparatively to determine x value in Si1-xGex layer, which show that while the two methods are consistent with each other when x is low, the results obtained from double crystals X-ray diffraction are not credible due to the large strain relaxation occurring in Si1-xGex layers when Ge content is higher than about 20%. Micro-Raman measurement is more appropriate for determining high Ge content than DCXRD.展开更多
Germanium-tin films with rather high Sn content （28.04% and 29.61%） are deposited directly on Si （100） and Si （111） substrates by magnetron sputtering. The mechanism of the effect of rapid thermal annealing on t...Germanium-tin films with rather high Sn content （28.04% and 29.61%） are deposited directly on Si （100） and Si （111） substrates by magnetron sputtering. The mechanism of the effect of rapid thermal annealing on the Sn surface segregation of Ge1-xSnx films is investigated by x-ray photoelectron spectroscopy （XPS） and atomic force microscopy （AFM）. The x-ray diffraction （XRD） is also performed to determine the crystallinities of the Ge1-xSnx films. The experimental results indicate that root mean square （RMS） values of the annealed samples are comparatively small and have no noticeable changes for the as-grown sample when annealing temperature is below 400℃. The diameter of the Sn three-dimensional （3D） island becomes larger than that of an as-grown sample when the annealing temperature is 700℃. In addition, the Sn surface composition decreases when annealing temperature ranges from 400℃ to 700℃. However, Sn bulk compositions in samples A and B are kept almost unchanged when the annealing temperature is below 600℃. The present investigation demonstrates that the crystallinity of Ge1-xSnx/Si （111） has no obvious advantage over that of Ge1-xSnx/Si （100） and the selection of Si （111） substrate is an effective method to improve the surface morphologies of Ge1-xSnx films. We also find that more severe Sn surface segregation occurs in the Ge1-xSnx/Si （111） sample during annealing than in the Ge1-xSnx/Si （100） sample.展开更多
基金This work is supported by the National Natural Science Foundation of China （Grant Nos. 60336010 ＆ 90401001）973 Program （Grant No. TG 2000036603）the Student Innovation Program of CAS （No. 1731000500010）.
文摘It is important to acquire the composition of Si1-xGex layer, especially that with high Ge content, epitaxied on Si substrate. Two nondestructive examination methods, double crystals X-ray diffraction （DCXRD） and micro-Raman measurement, were introduced comparatively to determine x value in Si1-xGex layer, which show that while the two methods are consistent with each other when x is low, the results obtained from double crystals X-ray diffraction are not credible due to the large strain relaxation occurring in Si1-xGex layers when Ge content is higher than about 20%. Micro-Raman measurement is more appropriate for determining high Ge content than DCXRD.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61474085 and 61704130)the Science Research Plan in Shaanxi Province,China(Grant No.2016GY-085)+1 种基金the Opening Project of Key Laboratory of Microelectronic Devices&Integrated Technology,Institute of Microelectronics,Chinese Academy of Sciences(Grant No.90109162905)the Fundamental Research Funds for the Central Universities,China(Grant No.61704130)
文摘Germanium-tin films with rather high Sn content （28.04% and 29.61%） are deposited directly on Si （100） and Si （111） substrates by magnetron sputtering. The mechanism of the effect of rapid thermal annealing on the Sn surface segregation of Ge1-xSnx films is investigated by x-ray photoelectron spectroscopy （XPS） and atomic force microscopy （AFM）. The x-ray diffraction （XRD） is also performed to determine the crystallinities of the Ge1-xSnx films. The experimental results indicate that root mean square （RMS） values of the annealed samples are comparatively small and have no noticeable changes for the as-grown sample when annealing temperature is below 400℃. The diameter of the Sn three-dimensional （3D） island becomes larger than that of an as-grown sample when the annealing temperature is 700℃. In addition, the Sn surface composition decreases when annealing temperature ranges from 400℃ to 700℃. However, Sn bulk compositions in samples A and B are kept almost unchanged when the annealing temperature is below 600℃. The present investigation demonstrates that the crystallinity of Ge1-xSnx/Si （111） has no obvious advantage over that of Ge1-xSnx/Si （100） and the selection of Si （111） substrate is an effective method to improve the surface morphologies of Ge1-xSnx films. We also find that more severe Sn surface segregation occurs in the Ge1-xSnx/Si （111） sample during annealing than in the Ge1-xSnx/Si （100） sample.
